Grade 3Science

Focus: This unit introduces Grade 3 students to real-world examples and fundamental concepts of forces, which will be explored in greater depth in later grades. Students will learn about observable effects of balanced and unbalanced forces on an object’s motion, describe and predict patterns of repeating motion, and explore how forces are associated with cause-and-effect relationships.

The relationship between forces and motion becomes clearer when students understand that:

  • a force is necessary to change an object’s motion;
  • if all the forces acting on an object are balanced, there will be no change in the motion of that object;
  • an object at rest is under the influence of balanced forces, for example a ball on the ground is pulled down by the force of gravity and pushed up by the force of the ground;
  • friction is a force that acts when surfaces are in contact; and
  • magnetism is a force that can act from a distance to push or pull.

Students also learn that engineers use their knowledge of forces as they develop solutions to problems and build things that are useful to people. As a series of culminating activities, students explore the principles and practices of engineering design, such as scientifically defining a problem to be solved using magnets, and evaluating and optimizing their possible solutions.

Number of Lessons: 9

Lesson Time: 3045 minutes daily. Each lesson may be divided into shorter segments.

Please note that certain lessons in this unit are designed for multiple days, resulting in approximately 15 days of instruction. For more information, please refer to the recommended Pacing Guide within the Teacher Guide.


Additional Search Terms:
force • motion • push • pull • balanced • unbalanced • gravity • predict/prediction • friction • lubricant • pattern • magnet/magnetism • problem • solution • test • nonfiction • informational text


CKSci Grade Levels: CKSci units are correlated to topics at the grade levels specified in the K–5 Core Knowledge Science Sequence.

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